11th Street bridges design makes some improvements

JDLand got a copy of the current design for the 11th Street bridges project. The original EIS showed a potential layout for the ramps and bridges, but DDOT asked engineering firms bidding on the project to design their own implementations.

The winning proposal, from Skanska/Facchina, would improve on the original design in a few ways. It places the two bridges (highway and local) closer together, shrinking the overall footprint of the project. It also lowers some ramps on the Anacostia side, allowing trees to obscure the view of the ramps from Ridge Place and other residential streets. And the firm claims that they can build 75% of the project without disrupting the existing traffic flow, by building new segments and ramps next to or around existing ones.

According to DDOT Director Gabe Klein, DDOT was able to mix and match some features from various proposals. It's not clear whether this is the blended design or just S/F's original suggestion. A few potential improvements jump out. Southbound on the local bridge, the original EIS showed a fairly sharp right turn to Good Hope Road and the freeway. S/F, instead, places a gentler turning ramp to Good Hope while keeping a sharp turn to the freeway. They have space to do that because they've moved the local bridge closer to the freeway bridge. However, it would be even better to just keep the sharper turn, allowing for even more space in Anacostia Park uninterrupted by freeway ramps. The sharper turn would also encourage lower speeds on the local bridge, which is not supposed to be for high-speed traffic and will accommodate pedestrians, bicycles and potentially streetcars.

The freeway bridge seems to have two ramps exiting as drivers reach capitol hill heading northbound. The original EIS only showed one, to M Street I can't figure out why there are two here. These ramps seem to also spread more widely away from the freeway. That might be an effort to build more of the project without disrupting the existing project. However, if the ramps hugged the freeway more closely, that would leave land along 12th Street that could one day be developed. Similarly, from the drawing it appears they are moving 12th Street over a little bit. If so, it's not clear why.

JD also notices that some of the ramps are missing in the drawing; according to a commenter, DC only has $230 million of the $360 for the full project, and has bid out the first portion to start.

Update: kk points out that the current ramps let drivers use either the local or freeway bridges to cross the river from Capitol Hill and access 295. In fact, if the freeway bridge gets backed up, it appears to be very easy for drivers to get off 295, take the local bridge, and then hop back on the freeway at the other end. The purpose of the local bridge is to accommodate traffic between the neighborhoods on either end, not to function as even more lanes for through traffic or to be a very expensive, very long off-ramp from the freeway to Capitol Hill.

Perhaps the interchange with the Anacostia Freeway should prevent cars from getting off the freeway and turning onto the bridge, or entering the freeway from the bridge. If drivers on the Capitol Hill side want to get on the freeway, they should get on the freeway side of the bridge instead. Doing this would also simplify the intersection where C-1, C-2 and C-4 all meet. Plus, this could allow narrower ramps, which might save money that DC could use to pay for the rest of the project.

David Alpert is the founder of Greater Greater Washington and its board president. He worked as a Product Manager for Google for six years and has lived in the Boston, San Francisco, and New York metro areas in addition to Washington, DC. He now lives with his wife and two children in Dupont Circle.

looking at the old and new drawings side-by-side, it appears that kk's second concern (being able to get onto northbound DC 295 (kenilworth ave.) from either bridge) exists in both plans. it doesn't appear to be something newly added to me. am i wrong?

C1/C2/C4 is functionally the same as a standard 4-way intersection, except for missing one outbound leg. If they prohibit a "through movement" from C4 to C2, it can easily be accommodated with a 3-phase signal (3rd phase being the left turn from SB 11th to ramp C2).

Yes, there's access to NB Kenilworth from both the local and freeway bridges...this hasn't changed at all. And the reason is so that there's a local access connection to/from Kenilworth.

Froggie, direct local access to Kenilworth should only be necessary to and from the east. Traffic from local streets on the west side of the bridge can use the ramps on the west side to go both NB and SB. It's important to have a minimum of freeway-bound traffic racing across and/or clogging up the local bridge.

And the C1/2/3 intersection could be further simplified and brought down to just 2 phases by eliminating the left onto NB Kenilworth and the left turn from C4.

I also agree with David's comment about that ramp to Good Hope Rd.- it wastes space and will encourage people to take the corner faster.

this new proposal is horrible for the neighborhood of anacostia. sure, they lowered ramps, which one one of my main suggestions -- but by allowing access for Everyone on the local bridge, it just clogs our bridge, making it even More inconvenient to get to our neighborhood then they are already making it, while providing maximum benefit to Marylanders.

Best use of stimulus highway money would have been to tear down Anacostia Freeway, center leg freeway and SE/SW Freeway as is the long term goal so neighborhoods can develop. Can't believe enlargement of this complex is the best DC had available.

Im all for having seperate bridges but this whole plan is just stupid; your creating an eye sore with all of the ramps. The design does not do anything for people who have to go anywhere besides to the other side of the river if you need to go anywhere out side of the other side of the river or 295 north you have to jump through hoops to get there. There are no connections with the 295 bridge at all you would have to get on or off one go through city streets and get back on the other. The whole mess takes up way to much space which could be overcome with tunnels on some portions such as the portions on the Anacostia side

If the plan was just a local bridge then there should be no ramps to the Anacostia freeway at all. The plan just needs to be scrapped and they need to start back from the drawing bored.

Simply destroying freeways is parchialism that further divides the area regionally.

Infinitely better is covering the freeways, and connecting the freeways as covered for the best of all.

I don't like the 11th Street bridge project as recreating and perpetuating the elevated portion of the SE Freeway, for the sake of rising to cross over a heavy rr tunnel that will be converted to lighter rail which can take the necessary grade change) and for destroying the eastern portion of the SE Freeway which should be extended and covered with a waterfront terrace.

As the current project to cover the Center Leg indicates, coverways are the way!

It is a total disgrace that Obama does not use stimulus money for this, and is but another indicator of who he belongs to.

Richard: from my viewpoint, the only freeway-bound traffic that would be crossing the local bridge is traffic coming out of the N and O St gates at the Navy Yard, which in my experience is not a whole lot.

The other factor to consider (probably negatively by most people here) is Federal policy which requires full interchanges on the Interstate system...no more partial interchanges. I don't necessarily agree with it, but it's likely the reason why the ramps remain at M St and a full interchange is planned at Kenilworth.

This new design seems oddly half-baked. Moving the bridges closer appears to create the need for all new piers on the new bridges - are they on the same footprints as the old ones? If the answer is no, I am guessing that's a budget buster. Dredging, remediation, engineering studies, etc.

It is hard to read this map. Am I correct that they are proposing to dump large amounts of traffic onto 10th St. where the Tyler School is. Doesn't that seem dangerous? I have to be wrong about this, right?